Various devices have been developed for the lifting or other movement of relatively large and/or bulky articles. A particular area of need for such devices is in the field of aviation, where such devices are generally used for loading ordnance and external stores on military aircraft, and for the installation and removal of engines from various civil and military aircraft.
Most such devices are essentially lifting platforms, and as such any motion in the horizontal plane must be provided by moving the vehicle upon which the lifting platform or device is installed. Even in those lifting devices which also provide for motion in the horizontal plane, such horizontal motion is generally provided along only a single axis. No such devices are known which provide for motion in any direction in the horizontal plane as well as along the vertical axis, and further provide angular or rotational motion as well, in the manner of the present invention.
It will be appreciated that such a device would result in a considerable savings of labor, as well as increasing safety to a great degree. Aircraft engines particularly have a variety of mounting points which must be precisely aligned with the cooperating points in the aircraft, and the inaccurate placement of the engine in the lifting device may result in a great deal of difficulty in the installation of the engine in the aircraft if that engine is supported by a lifting device which does not provide for motion in all of the generally accepted six degrees of motion. Indeed, a tragic accident occurred in 1979 due to the inadequacies of engine lifting devices, when a jet engine physically separated from the remainder of an air carrier aircraft on takeoff from Chicago's O'Hare Airport. The cause was determined to be a damaged mount on the engine due to a fork lift being used to support and transport the engine for installation on the aircraft. While procedures were in place to prevent such damage, the devices used with those procedures were, and still are, cumbersome, difficult, and time consuming to use.
The need arises for improvements in lifting and/or motion translation devices which improvements will provide for linear and angular motion along and about all three axes, thus providing six degrees of motion. An important feature of such a device is to provide for the recording of the forces and torques involved in operation over a period of time, in order to show evidence of the operating procedures used in a given operation should a question arise subsequently. The improvements must further provide for easy operation by a single person using a simple controlling device, which device should provide positive pressure feedback to the operator in order for the operator to more accurately sense the forces and torques involved.